The maximum value for the starting friction torque stated in the table is taken from the ABMA standard for instrument ball bearings.
Applicable Conditions
- Ball bearings in ABEC 7P quality (with or without shields)
- Stainless steel (e.g. AISI 440C) and chrome steel (AISI 52100) materials
- Two-piece cage design
- Lubricated with instrument oil
These values are maximum values for myonic ball bearings of the relevant category.
Starting Friction Torque Specifications
| Bore diameter d (inch) | Outer diameter D (inch) | Test load (N) | Maximum starting frictional torque (μN·m) | ||
|---|---|---|---|---|---|
| Press fit | Normal fit | Loose fit | |||
| 0.0001"-0.0003" (2-8 μm) | 0.0002"-0.0005" (5-12 μm) | 0.0005"-0.0008" (12-20 μm) | |||
| .0400 | .1250 | 0.75 | 18 | 15 | 14 |
| .0469 | .1563 | 0.75 | 18 | 15 | 14 |
| .0550 | .1875 | 0.75 | 18 | 15 | 14 |
| .0781 | .2500 | 0.75 | 18 | 15 | 14 |
| .0938 | .3125 | 0.75 | 18 | 15 | 14 |
| .1250 | .2500 | 0.75 | 18 | 15 | 14 |
| .1250 | .3125 | 0.75 | 18 | 15 | 14 |
| .1250 | .3750 | 0.75 | 20 | 15 | 15 |
| .1250 | .3750 | 4 | 50 | 45 | 42 |
| .1250 | .5000 | 4 | 50 | 45 | 42 |
| .1563 | .3125 | 0.75 | 18 | 15 | 14 |
| .1875 | .3125 | 0.75 | 18 | 15 | 14 |
| .1875 | .3750 | 0.75 | 20 | 16 | 15 |
| .1875 | .5000 | 4 | 65 | 55 | 50 |
| .2500 | .3750 | 0.75 | 18 | 15 | 14 |
| .2500 | .5000 | 4 | 60 | 52 | 48 |
| .2500 | .6250 | 4 | 70 | 60 | 55 |
| .2500 | .7500 | 4 | 80 | 70 | 65 |
| .3750 | .8750 | 4 | 110 | 95 | 90 |